Fiber optics represent an expanding field of telecommunications, wherein information is transmitted via light, and non-visible wavelengths such as infrared, through light-permeable “optical” fibers. In the fabrication of fiber-optic networks, optical fibers are routinely joined end-to-end to extend or redirect the path of the information-bearing light signals.
Common single-mode optical fibers, however, typically have a diameter of only about 8 to 9 μm, which makes the process of end-to-end alignment very slow, laborious, and expensive. Makers of automation equipment have addressed this alignment problem with only modest success. Equipment costing up to $1-million can align a fiber to another fiber or to an optical device, but only after a tedious “rough alignment” has been performed manually. Though, in this context, “rough” alignment, is a misnomer since very-high precision is required to enable some amount of light to be transmitted from one optical fiber to the other. Once light is being transmitted across the optical fibers, the automated equipment can move one of the fibers via an active-alignment process to improve the end-to-end alignment and thereby increase the amount of light transmitted across the fibers.
The rough alignment can be performed for up to several minutes before the fibers are close enough for “first light,” where the alignments of the fibers at least overlap so that sufficient light is transmitted across the fibers to begin the active alignment. Once active alignment begins, the robotic equipment may need several more minutes to center the fibers. The fibers can then, finally, be joined.